OHS legislation states that workers cannot be exposed to a noise that exceeds 85 dBA in an 8 hour work day. Once noise exceeds that level workers must reduce their exposure if not wearing hearing protection or wear the correct hearing protection (ear plugs or noise cancelling head phones). You can measure the noise levels using a sound meter or a mobile app.
OHS Code: Selection of Hearing Protection Devices
| Maximum equivalent noise level |
CSA Class of hearing protection |
CSA Grade of hearing protection |
| (dBA Lex) | ||
| ≤ 90 | C, B or A | 1, 2, 3, or 4 |
| ≤ 95 | B or A | 2, 3, or 4 |
| ≤ 100 | A | 3 or 4 |
| ≤ 105 | A | 4 |
| ≤ 110 | A earplug + A or B earmuff |
3 or 4 earplug + 2, 3, or 4 earmuff |
| > 110 | A plug + A or B earmuff and limited exposure time to keep sound reaching the worker’s ear drum below 85 dBA Lex | 3 or 4 earplug + 2, 3, or 4 earmuff and limited exposure time to keep sound reaching the worker’s ear drum below 85 dBA Lex |
OHS Code: Occupational Exposure Limits (OELs)
| Exposure level | Exposure duration |
| (dBA) | |
| 82 | 16 hours |
| 83 | 12 hours and 41minutes |
| 84 | 10 hours and 4 minutes |
| 85 | 8 hours |
| 88 | 4 hours |
| 91 | 2 hours |
| 94 | 1 hour |
| 97 | 30 minutes |
| 100 | 15 minutes |
| 103 | 8 minutes |
| 106 | 4 minutes |
| 109 | 2 minutes |
| 112 | 56 seconds |
| ≥ 115 | 0 |